Gas turbine engines, such as turbofan gas turbine engines, may be used to power various types of vehicles and systems, such as, for example, aircraft. Typically, these engines include turbine blades that are impinged on by high-energy compressed air that causes a turbine of the engine to rotate at a high speed. Consequently, the blades are subjected to high heat and stress loadings which, over time, may reduce their structural integrity.
To improve blade structural integrity, a blade cooling scheme is typically incorporated into the turbines. The blade cooling scheme directs cooling air through an internal cooling circuit formed in the blade to maintain blade temperatures within acceptable limits. The internal cooling circuit may include a simple channel extending through a length of the blade or may consist of a series of connected, serpentine cooling passages, which incorporate raised or depressed structures therein. The serpentine cooling passages increase the cooling effectiveness by extending the length of the air flow path. In this regard, the blade may have multiple internal walls that form the intricate cooling passages through which the cooling air flows. The cooling passages then direct the cooling air to openings on a tip and a trailing edge of the blade.
As the desire for increased engine efficiency continues to rise, engine components are increasingly being subjected to higher and higher operating temperatures. For example, newer engine designs may employ operating temperatures that are about 150° C. higher than conventional operating temperatures. However, current engine components, such as the blades, may not be as efficiently designed as desired. For example, certain portions of the blade, such as a platform of the blade, draw cooling air from the internal cooling circuit. However, bleeding cooling air from the internal cooling circuit can increase pressure loss. Additionally, in an event in which a structure of the internal cooling circuit is compromised, platform cooling may be adversely affected.
Accordingly, it is desirable to have an improved system for cooling a blade. In addition, it is desirable to for the improved system to adequately cool the blade platform with minimal pressure loss. Furthermore, other desirable features and characteristics of the inventive subject matter will become apparent from the subsequent detailed description of the inventive subject matter and the appended claims, taken in conjunction with the accompanying drawings and this background of the inventive subject matter.